1. Field of the Invention
The present invention relates to an intravascular endoscope apparatus for observing the interior of a blood vessel of a patient.
2. Description of the Related Art
A method using an intravascular endoscope is known as a means for observing the interior of a blood vessel of a patient. In this method, a blood vessel of a patient is partially incised, and an insert portion of the intravascular endoscope is inserted into the blood vessel through the incised portion to observe the interior of the blood vessel. In this case, the blood in the blood vessel interferes with a field of view. Therefore, a physiological saline solution is sprayed into the blood vessel from a distal end portion of the insert portion of the intravascular endoscope, and the blood in the field of view is temporarily scattered. While the field of view is assured in this state, observation is performed.
An image observed by the intravascular endoscope can be recorded on a photograph or a video tape. However, as described above, a recording operation need be performed within a moment when the physiological saline solution is sprayed into the blood vessel to scatter the blood, and the field of view is assured.
As described above, however, an operation for spraying the physiological saline solution from the intravascular endoscope and an operation for recording the observed image are performed by manual operations of an operator. For this reason, it is difficult to perform an accurate and stable recording operation.
In order to solve the above problem, as disclosed in Japanese Patent Disclosure (Kokai) No. 61-259635, a spray operation of a physiological saline solution and a recording operation of an image are automatically performed at predetermined timings based on an operation by an operator.
A time lag is present until the field of view in the blood vessel is assured after the spray operation of the physiological saline solution is started. In addition, this time lag varies depending on the length of a tube for the physiological saline solution, the pressure of a pump, and an influence of a blood pressure of a patient.
In the above-described conventional endoscope, therefore, since a recording operation is undesirably started before the field of view is assured even if the spraying operation of the physiological saline solution and the recording operation of the image are performed at proper timings, a film or a video tape serving as a recording medium is wasted.
In the above-described conventional endoscope, the spray operation of the physiological saline solution and the recording operation of the image are synchronously stopped. However, even if the spray operation of the physiological saline solution is stopped, the field of view is not abruptly lost. As a result, an effective image is undesirably missed.
More specifically, although it is preferable that the spraying operation of the physiological saline solution and the recording operation of the image are completed within a short period of time, the recording operation must be repeated in a state wherein the effective image is missed as described above, thus prolonging the recording time.